| Abstract [eng] |
Fast depletion of fossil fuels resources is an important problem, which can be solved by developing and employing energy generating technologies reliant on renewable energy sources. One of them – photovoltaic systems, which converts Sun’s emitted energy into electricity. Currently, perovskite solar cells are one of the most promising technologies and their power conversion was increased from 3.2 % up to 25.2 % over a short period of time. High efficiency is often achieved using dopants, which increase the conductivity of charge transporting materials. However, most of the compounds suitable for doping tend to accelerate degradation processes, therefore, perovskite solar cells suffer from relatively poor long-term stability. The aim of this work is to synthesize new organic metal complexes as semiconductors applicable in construction of perovskite solar cells and precursors, used for copper (I) thiocyanate layer formation. Metal complex semiconductors were intended to be used as dopant-free hole transporting materials, which would increase stability of the devices, compared with doped ones. Copper (I) thiocyanate precursors were synthesized and studied with the goal of replacing currently used relatively complicated layer formation methods of CuSCN. In this work three organic metal complexes, containing Ag, Cu (I), Cu (II) cations and sixteen copper (I) thiocyanate precursors, containing different organic ligands, were synthesized. Studies have revealed that all three metal complex semiconductors are thermally and morphologically stable while their energy levels are suitable for application in perovskite solar cells. Using these compounds as dopant-free hole transporting materials, perovskite solar cells demonstrated relatively high efficiencies, which surpassed dopant-free devices using Spiro-OMeTAD as a standard. Moreover, perovskite solar cells based on Cu (II) complex demonstrated improved stability, compared with Spiro-OMeTAD. Investigation of copper (I) thiocyanate precursors revealed that the most promising precursors were complexes containing different pyridine, imidazole and tri-tert-butylphosphine ligands. Applying mentioned compounds, copper (I) thiocyanate layer can be deposited both on inverted and non-inverted perovskite solar cells using DMSO and CHCl3 as solvents, respectively. |
